Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Duration of hospital stay
Systematic review	1255 people with acute cholecystitis 12 RCTs in this analysis	Duration of hospital stay 9.6 days with early cholecystectomy (open or laparoscopic) 17.8 days with delayed cholecystectomy (open or laparoscopic)	P <0.0001	Effect size not calculated	early cholecystectomy
Systematic review	1014 people with acute cholecystitis 10 RCTs in this analysis 6 RCTs included in review	Duration of hospital stay with early cholecystectomy (open and laparoscopic) with delayed cholecystectomy (open and laparoscopic) Absolute results not reported	Mean difference –2.7 days 95% CI –4.9 days to –0.49 days with early v delayed laparoscopic cholecystectomy Mean difference –10.2 days 95% CI –13.4 days to –7.0 days with early v delayed open cholecystectomy	Effect size not calculated	early cholecystectomy
Systematic review	388 people with acute cholecystitis 4 RCTs in this analysis	Duration of hospital stay with early laparoscopic cholecystectomy with delayed laparoscopic cholecystectomy Absolute numbers not reported	Mean difference –4.12 days 95% CI –5.22 days to –3.03 days P <0.001	Effect size not calculated	early cholecystectomy
Systematic review	243 people with acute cholecystitis 3 RCTs in this analysis	Duration of postoperative hospital stay with early laparoscopic cholecystectomy with delayed laparoscopic cholecystectomy Absolute numbers not reported	WMD 0.39 95% CI 0.13 to 0.66 P = 0.004	Effect size not calculated	delayed cholecystectomy
Systematic review	346 people with acute cholecystitis 3 RCTs in this analysis	Duration of hospital stay with early laparoscopic cholecystectomy with delayed laparoscopic cholecystectomy Absolute results not reported	WMD –1.14 95% CI –1.58 to –0.70 P <0.001	Effect size not calculated	early cholecystectomy
Postoperative complications
Systematic review	916 people with acute cholecystitis 9 RCTs in this analysis	Postoperative complications with early open cholecystectomy with delayed open cholecystectomy Absolute results not reported	OR 0.95 95% CI 0.66 to 1.38		Not significant
Systematic review	228 people with acute cholecystitis 3 RCTs in this analysis	Postoperative complications with early laparoscopic cholecystectomy with delayed laparoscopic cholecystectomy Absolute results not reported	OR 0.69 95% CI 0.27 to 1.73		Not significant
Systematic review	451 people with acute cholecystitis 5 RCTs in this analysis	Proportion of people with bile duct injury 1/222 (0.5%) with early laparoscopic cholecystectomy 3/216 (1.5%) with delayed laparoscopic cholecystectomy	RR 0.64 95% CI 0.15 to 2.65 P = 0.54		Not significant
Systematic review	375 people with acute cholecystitis 4 RCTs in this analysis	Proportion of people with bile leak with early laparoscopic cholecystectomy with delayed laparoscopic cholecystectomy Absolute numbers not reported	OR 2.42 95% CI 0.75 to 7.74 P = 0.14		Not significant
Systematic review	504 people with acute cholecystitis 4 RCTs in this analysis	Proportion of people with bile leak 7/254 (0.3%) with early laparoscopic cholecystectomy 2/237 (0.1%) with delayed laparoscopic cholecystectomy	OR 2.22 95% CI 0.60 to 7.72 P = 0.21		Not significant
Systematic review	504 people with acute cholecystitis 4 RCTs in this analysis	Overall complications 36/254 (14%) with early laparoscopic cholecystectomy 35/237 (15%) with delayed laparoscopic cholecystectomy	OR 0.97 95% CI 0.59 to 1.61 P = 0.91		Not significant
Systematic review	504 people with acute cholecystitis 4 RCTs in this analysis	Intra-abdominal collection 11/254 (4%) with early laparoscopic cholecystectomy 8/237 (3%) with delayed laparoscopic cholecystectomy	OR 1.28 95% CI 0.51 to 3.25 P = 0.60		Not significant